A 45-year-old man with septic shock has a serum lactate of 6.8 mmol/L on admission. After 6 hours of resuscitation with antibiotics and fluids, his lactate drops to 3.2 mmol/L. What does this lactate clearance indicate?

• A The patient has developed lactic acidosis from thiamine deficiency
• B The patient requires immediate hemodialysis
• C Tissue perfusion is improving and mortality risk is reduced ✓
• D Metformin toxicity is the likely cause

Explanation

Lactate clearance of >10% within 6 hours of resuscitation in septic shock is associated with improved outcomes and reduced mortality. Serum lactate reflects the balance between production (from tissue hypoperfusion and anaerobic metabolism) and clearance (hepatic and renal). A falling lactate indicates improved tissue oxygen delivery. Persistent hyperlactatemia despite adequate resuscitation portends worse prognosis and may indicate ongoing tissue hypoxia or mitochondrial dysfunction.

Reference: Surviving Sepsis Campaign Guidelines, 2021 ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.